Chapter III: HETEROTRICHIA, Massee. Sporangia regular, oblong-ovoid, stipitate;

the wall a thin delicate membrane, the upper part disappearing at maturity, leaving the basal portion as a small calyculus. Stipe filled with large thick-walled vesicles, which are sub-angular from mutual pressure; these become smaller upward, and pass gradually into normal spores. Capillitium issuing from the interior of the stipe, the central and superficial threads dissimilar, forming a complicated network, with numerous free extremities, the surface minutely warted, or with annular ridges. Spores globose, brownish.

Distinguished from Arcyria by the numerous free extremities of the peripheral portion of the network.

1. HETEROTRICHIA GABRIELLÆ, Massee. Sporangium oblong-ovoid, stipitate; the calyculus small, thin, smooth. Stipe very short, erect, yellowish-brown in color. Capillitium much elongated after dehiscence, cylindric-ovoid, sub-erect; the threads of the central portion about 1.5 mic. thick, with slightly elevated ridges partly encircling the tube, nearly colorless; threads of the peripheral portion bright yellow, 5-6 mic. thick, with numerous short acute free branches, the surface densely and minutely warted. Spores in mass, yellowish-brown, globose, even, 7-8 mic. in diameter. See Plate I, Fig. 18.

Growing on wood; S. Carolina, _H. W. Ravenel_. The sporangia densely crowded, becoming scattered toward the margin of the cluster. Massee's Monograph of the Myxogasters.

ORDER V. TRICHIACEÆ.

Sporangium regular and stipitate or sessile, rarely plasmodiocarp; the wall a thin membrane, usually granular or venulose on the inner surface, colored as the spores and capillitium, irregularly dehiscent. Capillitium of slender tubules, simple or branched, scarcely forming an evident network; the surface of the threads furnished with continuous ridges, which wind around the tube in a spiral manner. Spores globose, red, brown, yellow, olivaceous.

This order is readily recognized by the spiral ridges which wind around the tubules of the capillitium.

TABLE OF GENERA OF TRICHIACEÆ.

1. HEMIARCYRIA. Capillitium of long slender tubules, arising from the base of the sporangium, or issuing from the interior of the stipe; the spiral ridges parallel and conspicuous.

2. CALONEMA. Capillitium of slender tubules, arising from the base of the sporangium; the surface traversed by a system of branching veins.

3. TRICHIA. Capillitium consisting of numerous short slender tubules, called elaters, which are wholly free; the spiral ridges parallel and conspicuous.

4. OLIGONEMA. Capillitium scanty, composed of elaters habitually irregular and abnormal; the surface variously marked.